Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 247, NWS Philadelphia/Mount Holly

August 23, 2020Kent County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 23, 2020, 7:58 PM EDT for Kent County, Maryland. It was in force for 25 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 23, 2020, 7:58 PM EDT (23:58 UTC)
Expired
Aug 23, 2020, 8:23 PM EDT
In force
25 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Kent County, MD

The radar

The Dover AFB radar (KDOX), 75 km from the middle of the area, began a volume at 00:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 12.0 hours before the alert went out and 114 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2020-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1048 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2020-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1048 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
721 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

538 
WUUS51 KPHI 232358
SVRPHI
MDC029-240045-
/O.NEW.KPHI.SV.W.0247.200823T2358Z-200824T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
758 PM EDT Sun Aug 23 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Kent County in northeastern Maryland...

* Until 845 PM EDT.

* At 758 PM EDT, a severe thunderstorm was located near Rock Hall, or
  7 miles east of Millers Island, moving east at 30 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Chestertown, Rock Hall, Betterton, Newtown, Old Town, Langford and
  Kingstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

For your protection move to an interior room on the lowest floor of a
building.

In addition to hail and damaging winds, frequent cloud to ground 
lightning is occurring with this storm. Move indoors immediately. 
Remember, if you can hear thunder, you are close enough to be struck 
by lightning.

&&

LAT...LON 3926 7622 3929 7617 3932 7618 3934 7616
      3933 7614 3937 7611 3938 7602 3922 7604
      3920 7607 3917 7604 3915 7609 3914 7607
      3910 7612 3909 7623 3917 7628
TIME...MOT...LOC 2358Z 270DEG 24KT 3922 7628 

HAIL...0.75IN
WIND...60MPH
 
$$

Gorse
2 follow-up statements
687 
WWUS51 KPHI 240008
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
808 PM EDT Sun Aug 23 2020

MDC029-240045-
/O.CON.KPHI.SV.W.0247.000000T0000Z-200824T0045Z/
Kent MD-
808 PM EDT Sun Aug 23 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHWESTERN KENT COUNTY...

At 807 PM EDT, a severe thunderstorm was located near Langford, or 11
miles east of Millers Island, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Chestertown, Rock Hall, Betterton, Newtown, Old Town, Langford and
Kingstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

For your protection move to an interior room on the lowest floor of a
building.

Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.

&&

LAT...LON 3926 7622 3929 7617 3932 7618 3934 7616
      3933 7614 3937 7611 3938 7602 3922 7604
      3920 7607 3917 7604 3915 7609 3914 7607
      3910 7612 3909 7623 3917 7628
TIME...MOT...LOC 0007Z 272DEG 23KT 3921 7621 

HAIL...<.75IN
WIND...60MPH
 
$$

Gorse
841 
WWUS51 KPHI 240023
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
823 PM EDT Sun Aug 23 2020

MDC029-240033-
/O.CAN.KPHI.SV.W.0247.000000T0000Z-200824T0045Z/
Kent MD-
823 PM EDT Sun Aug 23 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN KENT COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

LAT...LON 3926 7622 3929 7617 3932 7618 3934 7616
      3933 7614 3937 7611 3938 7602 3922 7604
      3920 7607 3917 7604 3915 7609 3914 7607
      3910 7612 3909 7623 3917 7628
TIME...MOT...LOC 0022Z 270DEG 24KT 3921 7607 

$$

Gorse

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 23, 1:45 PM EDTSpecial Weather StatementPHICecil60 min
Aug 23, 5:17 PM EDTSpecial Weather StatementPHIKent28 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2020Every severe thunderstorm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.